Working in a hospital, I come across people with Munchausen's every once in a while. I remember one patient in particular, every time someone would look in her direction, she would suddenly start having a coughing fit or be in a lot of pain. It is a bit sad to see that people feel as though they have to resort to this to get some sort of care or attention. I'm not there to judge your sisters case, but I would try to keep a close eye on her, but not encourage the situation if she does in fact have Munchausen's. There have been plenty of times I've felt like I've had Munchausen's, simply because I knew and still know there is something wrong with me medically, but even though the symptoms are there, the test don't reveal enough to diagnose me with anything. Sometimes it is all in our head and other times it is really difficult to find someone that will believe you if your tests are panning out okay.